title: Breast boost using noninvasive image-guided breast brachytherapy vs. external beam: a 2:1 matched-pair analysis.
abstract: BACKGROUND
  To compare clinical outcomes and toxicity in patients treated with NIBB boost with those in patients treated with external beam (EB) boost.
  
  
  METHODS
  Women with early stage breast cancer treated with WBI and NIBB boost were identified. Control subjects treated with EB boost identified as the best possible match with respect to age, stage, chemotherapy use, and fractionation were chosen for a 2:1 comparison. Acute toxicity, late toxicity, and oncologic outcomes were reviewed. The McNemar nonparametric test was used to evaluate marginal homogeneity between matched pairs.
  
  
  RESULTS
  One hundred forty-one patients were included in the analysis: 47 patients treated with NIBB boost and 94 matched control subjects treated with EB boost (electron, n = 93) or 3-D conformal radiation (n = 1). Grade 2+ desquamation developed in 18 patients (39%) treated with NIBB boost and in 49 patients (52%) treated with EB boost (P = .07). Breast size, electron energy, and fractionation predicted for acute desquamation (P < .0001, P < .001, and P = .006). Median follow-up was 13.6 months. One patient (2%) who received NIBB had Grade 2+ skin/subcutaneous fibrosis 15 months after completion of treatment. Among those treated with EB, 9 patients (9.5%) developed Grade 2+ subcutaneous fibrosis, and 1 patient had recurrent cellulitis. There was statistically significantly less combined skin/subcutaneous toxicity in those treated with NIBB than in those treated with EB (P = .046).
  
  
  CONCLUSIONS
  NIBB boost is associated with favorable short-term clinical outcomes compared with EB.
authors.affiliation: Department of Radiation Oncology, Rhode Island Hospital, Brown Alpert Medical School, Providence, RI; Department of Radiation Oncology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA. Electronic address: karalynne.kerr@gmail.com.
authors.forename: Kara Lynne
authors.initials: KL
authors.lastname: Leonard
authors.forename: Jaroslaw T
authors.initials: JT
authors.lastname: Hepel
authors.forename: John R
authors.initials: JR
authors.lastname: Styczynski
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Hiatt
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Dipetrillo
authors.forename: David E
authors.initials: DE
authors.lastname: Wazer
mesh_terms: D001918:Brachytherapy; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D016022:Case-Control Studies; D019583:Dose Fractionation, Radiation; D004583:Electrons; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016555:Matched-Pair Analysis; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D061089:Radiotherapy, Image-Guided
keywords: AccuBoost; Brachytherapy; Breast boost; Breast cancer; NIBB